# CVE-2026-12611: Race condition in Eclipse Jetty

> A race condition in Jetty server allows remote attackers to cause a denial of service by blocking all server threads via specific HTTP/2 frames.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 8 Sep 2026
- **Updated:** 9 Sep 2026
- **Also known as:** DEBIAN-CVE-2026-12611, GHSA-gpg9-4257-cfm3, GHSA-v2pm-593h-x95w, UBUNTU-CVE-2026-12611, openSUSE-SU-2026:11804-1

## What is CVE-2026-12611?

CVE-2026-12611 is a high-severity vulnerability in Eclipse Jetty, published on 8 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A client may issue HTTP/2 requests to a Jetty server that result in blocking writes that are never unblocked, eventually causing all threads to be blocked and the whole server to become unresponsive.

This is caused by a race condition in the server when handling RST_STREAM frames and GOAWAY frames sent by the client.

The race condition "resets" the HTTP2Flusher.terminated, previously set to a non-null value, to the null value, allowing entries to be enqueued in the flusher that however will never be processed. These unprocessed entries are the ones that would unblock the write-blocked threads.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2026-12611?


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `jetty-minimal` | openSUSE:Tumbleweed | All versions | 9.4.58-6.1 |

## How do I fix CVE-2026-12611?

Apply the vendor's patch.

## Is CVE-2026-12611 being exploited?

There is no known exploitation of CVE-2026-12611 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-12611 and fix it if it is affected.

What it is: CVE-2026-12611 is a high-severity vulnerability in Eclipse Jetty, published on 8 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-12611 in the wild and no public exploit code.

Affected product: Eclipse Jetty. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-12611/ (Markdown: https://insights.sbomify.com/CVE-2026-12611/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-12611
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-12611
- OSV: https://osv.dev/vulnerability/CVE-2026-12611

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-12611/
Summaries are generated and may contain mistakes; the official description above is the record.